Unithas0.2MMSlottedbasket
5FoilRotorDesign
HasMechanicalseal
BeltDriven
Unitis316SS
TheSPMpressureScreenincludesacylindricalplatecontainedinapressurizedcase,arotatingfoilassembly,aunitizedbase,sheavesandbelts,motormountingbracketonsliderailsanda200hpdrivemotor.
Thepressurizedcaseisessentiallysflangedcylinderwithadomedtopclosure.Thestandardcasehasapressureratingof60psi(4bars).Thereare3connectionstothemainbodyofthecase.Theyarejoinedtothecasecylinder.Thelargerupperconnectionisforincomingstockwhilethesmallerconnection,nearthebottomisanoutletforrejects.Thelowerportionofthecaseisforcollectingacceptedstock(accepts)afteritpassesthroughthescreenplate.Theacceptsoutletconnection,inthedomeofthecase,bleedsentrappedairfromthepressurescreen.
ThedrivemotorismountedverticallyonanL-shapedmotorbasewhichmountsonasliderail.SmatchedsetofV-beltsconnectsthemotorandpressurescreen.
Incomingstocktobescreened,entersthecasethroughtheupperinletconnectionandisimmediatelyacceleratedbythefoilassemblysweepingaroundthescreen.Theresultantcentrifugalforcethrowsheavydensecontaminantsawayfromthescreenplateandagainstthesidesofthecasewheretheyareflushedoutthroughtherejectsoutlet.Stockflowisinward(centripetal)throughthescreenplate.Acceptedstockcollectedinthecentercompartmentflowsdownwardandouttheacceptsconnection.Duetotheactionofthefoilassembly,thetangentialvelocityacrossthesurfaceoftheplateexceedstheinwardcentripetalflowvelocitybyafactorofabout10.Thiscausesstocktoapproachthescreenplateatanextremelylowangleandsignificantlyreducestheeffectivesizeofthescreenplateopeningsand,therebyincreasesscreeningefficiency.
Rejectmaterialmigratesspirallydownwardthroughtheoutercompartmentandouttherejectsconnection.
Thescreenidessentiallyselfcleaningbecauseofthehydrodynamiccharacteristicsofthehydrofoil.Eachfoilgeneratedahighnegativepressurepulsethatnotonlybreaksupthefibermatformedovertheplate,butalsoliterallypullslodgedparticlesfromthescreenplateanddepositstheminthefastmovingtangentialflowaroundthescreen.Ifparticlesaredense,centrifugalforceslingsthemtotheouterwallwheretheyarecollectedattherejectsoutlet.
Theventatthetopofthehousingbleedsoffalowflowofstockand,withit,anyairthatmaybeentrainedintheinletstream.Somelightfloatingparticlesmaybecarriedoffwiththisstreamandshouldberejected,Theventmustbeopenduringstartupofthescreen,butmaybeclosedorthrottledduringoperationaftertheinitialairinthesystemhasbeenbledoff.
